The present invention relates generally to intelligent hard-target weapons, which depend on detonation taking place in a specified medium at a desired depth of the target.
The effectiveness of a penetrating weapon against hard targets is dependent on the detonation taking place in a specified medium at a desired depth of the target. These targets include high valued substances buried underground beneath several layers of concrete, steel, dirt, sand, etc.
It is essential for the fuze to have sufficient information on which medium the projectile is in to make an intelligent detonation decision. Sensors utilized for the penetrators are accelerometers to date.
The following U.S. patents are of interest.
4,375,192--Yates et al PA1 4,455,939--Munzel PA1 4,799,427--Held et al
Held et al discloses a projectile ignition device, wherein the ignition moment is controllable as a function of the impingement delay and of the flight time of the projectile. This allows compensation for the type of material comprising the target, e.g., hard or soft. The application is for penetrating into certain armor platings. The output signal 10 of the acceleration pickup sensor 1 (disposed in the projectile) activates the input of a threshold circuit 2. The output signal 10 may be either an output signal 11 or output signal 12 depending on the threshold value. Two embodiments are disclosed.
Yates et al discloses a programmable fuze for a weapon warhead which is designed to initiate detonation upon penetration of a target a preselected distance or after a preselected number of cavities. A triaxial accelerometer 10 measures the deceleration of the weapon as it enters a target. Zero slope detector 16 outputs a zero slope signal 161 which indicates that there is a discontinuity in density of the target material, i.e., a cavity in the target. Microcomputer 15 has an algorithm stored within a RAM and operates of the data field to determine if threshold values have been exceeded. Four fields of information are in a data word. Detonation depends on one of four possible conditions.
Munzel discloses an impact fuze with flight time-dependent detonation delay.